Branched polymers have different physical and chemical properties compared to their linear counterparts.1 An understanding of these properties has made these materials useful, for example for industrial and/or medical applications. Hyperbranched polymers exhibit a fractal pattern of bonding, and typically exhibit a greater degree of polydispersity than similar dendritic and linear polymers.2,3 Topologically speaking, hyperbranched polymers are composed of branched and terminal repeat units, along with linear units that contain unreacted functional groups. This class of materials can be initiated from a core molecule, although there are other known methods of preparing these polymers.4,5 
Hyperbranched polymers have been produced using a variety of catalysts to control morphology and mass dispersity. For example, titanium and dialkyl tin complexes have been used in the synthesis of branched polyesters.6-8 
Lipase catalysis was first used by Skaria et al. to generate branched polymers from ε-caprolactone and 2,2′-bis(hydroxymethyl)butanoic acid.9 Kulshrestha et al. employed N435 (an immobilized lipase B from Candida antarctica) in the synthesis of glycerol-based copolyesters from adipic acid, octan-1,8-diol and glycerol under solvent-free conditions.3 The regioselectivity for the primary alcohol of glycerol was independent of the glycerol concentration. However, the degree of branching could be varied between 9-58% by varying the feed ratio of glycerol. Triglyceride analogs derived from oleic diacid, linoleic acid and glycerol were also reported to be produced using an enzymatic method.10 
Polysiloxanes are a useful class of polymer owing to the alternating arrangement of silicon and oxygen atoms which imparts a high degree of flexibility to the polymer backbone. Siloxane-derived materials, for example, those comprising dimethylsiloxane units, can have useful physicochemical properties, such as resistance to oxidation, low permittivity, hydrophobicity, permeability to oxygen, low glass transition temperature and/or bio-compatibility.11-13 
Branched and cross-linked silicones can be prepared via hydrosilylation using one of several commercially available Pt0 or Rh1 catalysts, titanium isopropoxide and/or dibutyltin dilaurate. Alternatively, peroxide-induced free radical polymerization of acetoxy- or alkoxysilanes,14 photo-initiated polymerization,15 anionic polymerization16 and tris(pentafluoroborane) catalysis17-19 have been used to prepare a diverse range of siloxane architectures.
Enzymatic catalysis has been employed to produce polymers containing siloxane-derived fragments.20-29 In studies where both monomers were siloxane-derived, a degree of thermal protection was conferred to the enzyme catalyst.29 A study of the chain length selectivity of Candida antarctica lipase B (CalB) for trisiloxane-containing esters reported the role that steric interactions play in choosing appropriate siloxane substrates when using an enzyme catalyst.30 
Nanostructured siloxane materials are gaining popularity due the prospect of tailoring the spatial arrangement of functional groups in space and/or their use as precursors to stereoregular silsesquioxanes.31,32 However, to date, there are no known examples in the literature where biocatalysis or enzymatic catalysis has been employed to produce, or modify, oligocyclosiloxanes.
Spherosilicates are oligomeric silsesquioxanes derived from a Q8 core, composed of eight SiO4 units arranged in a cubic framework, rather than the more commonplace T8 framework in which the vertices of the cubic structure are functionalized with an organic moiety.
Spherosilicates have received attention as candidates for novel functionalized materials,33,34 encapsulants,35,36 and bioconjugation scaffolds37 and have been reviewed in the literature.38-40 
Spherosilicates can be modified with various functional groups, typically incorporated via hydrosilylation chemistry, allowing for the generation of new materials with tunable properties. For example, Jutzi et al. synthesized spherosilicates functionalized with decacarborane cages, ferrocene units and half-sandwich manganese carbonyl complexes.41 Alkyl chains, acrylates, esters, amines/amides, aryl ring systems, nitriles and alkoxysilyl groups have also been tethered to the Q8 core. Tethering acrylates to the eight vertices of the cube allows for cross-linking via atom transfer radical polymerization (ATRP). Another route examined by Costa et al. tethered 2-bromo-2-methylpropionyl bromide to a hydroxypropyldimethylsiloxy-functionalized Q8 cube to give an α-bromide ester suitable as an initiator for ATRP chemistry with methyl methacrylate.42 
Polymers, coatings and 3D stars comprising polyhedral silsesquioxanes have been reported. For example, Jung and Laine have reported “beads on a chain” polymers formed from the reaction of di- and triaminophenyl, phenyl silsesquioxane with the diglycidyl ether of bisphenol A to form a soluble epoxy resin.43 U.S. Pat. No. 7,868,198 discloses coatings incorporating multi-functional silsesquioxanes. Sulaiman et al. have reported 3-D stars with a silsesquioxane core which are disclosed to be useful for the synthesis of dendrimers or hyperbranched molecules.44 Asuncion and Laine have reported the reaction of octaaminophenylsilsesquioxane with epoxides and dianhydrides and their subsequent heat treatment to form nanocomposite films.45 
While many approaches have been reported for modifying the vertices of Q8 and T8 cubic octamers, to date an enzymatic approach has not been reported.